Samuel Clemens or Mark Twain. On his way down the Mississippi he decided that he wanted to be a pilot rather than writing on his trip. He spent two years as a cub pilot and received his pilot license in 1859 at the age of 23. He had his own boat for two years until the civil war cut him off. He picked up the term Mark Twain which is two fathoms deep. The term can be a good thing or a bad thing at the same time. When he returned to writing he started to use the name Mark Twain. Clemens was an apprentice for two years for a fee of five hundred. Sam relished the steamboat life with new passengers and different scenery as he went along. His pilot career was short lived because of the civil war which shut down with all traffic halted. Clemens ended up joining the militia which only lasted two weeks.